EHD making its ugly return

September 22, 2013

BISMARCK - The North Dakota Game and Fish Department announced this past week that the sale of more than 1,000 deer gun licenses has been suspended. The licenses, which were not purchased in the state's second round of the annual deer gun lottery, have been pulled due to a deer die-off caused by epizootic hemorrhagic disease, or EHD.

"The decision is based on previous years' experience where moderate to significant white-tailed deer losses were documented in situations similar to this year," said Randy Kreil, NDG&F wildlife division chief.

While EHD outbreaks are always possible, it is somewhat alarming that this year's outbreak follows a similar one in 2011 when Game and Fish offered refunds to deer gun license holders due to dwindling numbers of deer.

Article Photos

Submitted photoThe possible sale of more than 1,000 deer gun licenses in the three highlighted hunting units was halted by the North Dakota Game and Fish Department due to an outbreak of epizootic hemorrhagic disease.

How extensive this year's die-off will be has yet to be determined. EHD is carried by a biting midge that transfers the disease from one animal to another. Outbreaks end when freezing temperatures eliminate the midges.

"Those midges are in the highest densities in the southwest area of the state," said Jeb Williams, wildlife division assistant chief. "2011 and 2013 were both very wet years which is prime conditions for EHD."

EHD can be carried by animals seldom affected by the disease, such as livestock, mule deer and pronghorn antelope. Midges that bite those animals can carry the EHD virus to white-tailed deer, an animal that is particularly vulnerable to EHD.

"The midge acts as a vector when it bites one and then another. Boom! Done deal," said Williams.

White-tailed deer infected with EHD generally die within two or three days of contacting the virus. Infected animals run a high fever which causes them to seek water for the purpose of cooling down. Therefore, most deer that succumb to EHD are found in or adjacent to water.

"Once infected they are usually dead fairly fast," said Williams. "We've gotten some confirmed tests back. The trick is getting to an infected animal soon enough. We've even received e-mails of deer submerged in water but still alive. That's what's going on. Northwest South Dakota is experiencing the same thing."

According to Williams, Game and Fish had received more than 20 reports as of last week about dead or dying white-tailed deer.

"It involved over 100 deer from Bismarck all the way down to Bowman. That's just what has been reported," said Williams. "We've had reports as far north as McKenzie County, from Grant and Hettinger Counties, even Morton, Sioux and Burleigh."

Midges breed best on mud flats, such as those that occur when water in sloughs begin to recede in the fall. This year conditions in southwest North Dakota have been excellent for midges. How many deer have died, or will die, remains an unknown. The die-offs are not expected to come to a halt until a killing freeze occurs.

Montana experienced a severe EHD outbreak two years ago.

"Oh yeah, the white-tails got hammered in the eastern part of Montana. I mean really bad, especially along the Mussleshell," said Marshall Johnson, Billings, Mule Deer Foundation director for N.D. and Montana.

Although it is not fully known why, mule deer are generally not affected by EHD. That is good news for North Dakota's mule deer. The state's muley population had been in decline for five years due to difficult winter conditions over much of their western range. This year mule deer surveys showed a modest population increase. However, because mule deer numbers remain low, no mule deer doe hunting licenses were issued in 2012 or 2013.

Game and Fish has made inspections in reported EHD die-off areas but expects to receive more information during and after the opening weekend of the pheasant season Oct. 12.

"In 2011 we heard from a lot of pheasant hunters," noted Williams. "That is usually a big indicator. Those hunters get out and walk those drainages where a lot of die-offs might occur."

Fortunately, EHD is not known to transfer to humans. However, cautions Williams, Game and Fish recommends that hunters not eat any animals that appear sickly, no matter what the suspected cause.